Adjustable surgical sling

ABSTRACT

The invention, in one embodiment, is directed to systems and methods for adjusting support to an anatomical location using an expandable chamber.

FIELD OF THE INVENTION

The invention generally relates to surgically implantable slings. Morespecifically, in various embodiments, the invention is directed to asurgically implantable sling having an expandable supportive chamber.

BACKGROUND

Urinary incontinence affects over 13 million men and women of all agesin the United States. Stress urinary incontinence (SUI) affectsprimarily women and is generally caused by two conditions, intrinsicsphincter deficiency (ISD) and hypermobility. These conditions may occurindependently or in combination. In ISD, the urinary sphincter valve,located within the urethra, fails to close properly (coapt), causingurine to leak out of the urethra during stressful activity.Hypermobility is a condition in which the pelvic floor is distended,weakened, or damaged, causing the bladder neck and proximal urethra torotate and descend in response to increases in intra-abdominal pressure(e.g., due to sneezing, coughing, straining, etc.). The result is thatthere is an insufficient response time to promote urethral closure and,consequently, urine leakage and/or flow results.

A popular treatment of SUI is the use of a sling, which is permanentlyplaced under a patient's bladder neck or mid-urethra to provide aurethral platform. Placement of the sling limits the endopelvic fasciadrop, while providing compression to the urethral sphincter to improvecoaptation. Generally, the sling is surgically placed under urethra orbladder neck, close to the high-pressure zone with no elevation of theurethra. When abdominal pressure increases, the sling stops the descentof the urethra and functions as a mechanism of closure for the urethrato prevent urine leakage. However, if too much tension is applied, thepatient may go into urine retention, unable to void the bladder andsuffer a pressure build-up in the bladder. Such pressure build-up canlead to reflux of urine up the ureters and into the kidney, eventuallyresulting in kidney damage, and, potentially, kidney loss. If thetension is too small, the implanted sling may not perform its functionas intended. Clinically, there is technical challenge to position andapply the correct tension to the sling. Therefore, it is sometimesnecessary to modify the sling tension after the implantation surgery ofthe sling. Currently, there is no easy method to adjust the tension ofthe sling to compensate for the tension change of the sling over time.Therefore, improved surgically implantable slings, and methods to adjustthe sling tension are needed.

SUMMARY OF THE INVENTION

The invention provides, in various embodiments, devices and methodsrelating to surgically implantable slings. In one aspect, the inventionprovides a surgically implantable sling for the treatment of urinaryincontinence, which includes an expandable chamber intermediate to thetwo ends of the sling, in a portion of the sling that supports theurethra. The chamber, in one configuration, is shaped and sized suchthat the top surface of the chamber, which touches the urethra whensufficiently inflated, is generally flat, giving the chamber asubstantially rectangular cross-sectional outline. The chamber may befilled to varying degrees by injecting or removing a filling materialsinto or from the chamber. Depending on the degree of fullness of thechamber, the height of the chamber changes, thus changing the positionof the top surface of the chamber relative to the urethra. According toanother feature, the changes in chamber height change the degree towhich the sling generally and the top surface of the chamberspecifically support the urethra. According to a related feature,changing the chamber height causes tensioning of the sling to change.

According to some configurations, at least the portion of the topsurface supporting the urethra is maintained at approximately the sameor a lower height than that of peripherally located portions of the topsurface that do not contact the urethra, even when the chamber is invarious states of expansion. In this way, the invention reduces thelikelihood of the urethra rolling or sliding off the top surface of thechamber. It also reduces the likelihood of the chamber being displacedin such a way that the sling no longer properly supports the urethra.Although these height features are described in terms of reducing thelikelihood of a urethra rolling or sliding off the top surface of thechamber, such features are equally applicable to supporting anyanatomical location or feature.

In one embodiment, the expandable chamber has one or more throughpassages connecting the upper side and the lower side of chamber,externally giving the chamber a perforated configuration. Moreparticularly, in one configuration, the through passages extendingbetween the upper and lower sides form one or more walls that extendbetween and connect inner surfaces of the upper and lower sides of thechamber. According to one feature of this configuration, theperforations facilitate tissue in growth for effectively anchoring thechamber at a mid-urethral location. According to another feature, thewalls extending between and connecting the inner surfaces of the upperand lower sides of the chamber cause the outer surface of the upper sideto be substantially flat except for the through passages. According to afurther feature, the walls extending between and connecting the innersurfaces of the upper and lower sides of the chamber maintain a middleportion of the top surface of the upper side at approximately the sameor a lower height than a peripherally located portion of the topsurface, even when the chamber is expanded.

In another embodiment, the expandable chamber is divided by at least onedivider into sub-chambers that are in fluid communication with eachother. The divider extends between the inner surfaces of the upper andlower sides, and in certain embodiments, the dividers intersect with oneanother. In another illustrative embodiment, the expandable chamberincludes cord-like material extending between and connecting the upperand lower sides internal to the chamber.

In an alternative illustrative embodiment of the invention, the upperside of the expandable chamber is substantially rigid. In anotherillustrative embodiment, the expandable chamber has at least a pair ofopposing sides, each of their top and bottom edges are attached to theedges of the upper side and the lower side, respectively. The sides haveaccordion-like structures for expanding and contracting to increaseand/or decrease the height of the expandable chamber, in response to thechamber being inflated or deflated, respectively.

The expandable chamber of the sling assembly according to the inventioncan be constructed, at least in part, from a self-sealing material. Thefiller material can be injected directly into the chamber through theself-sealing material. In another embodiment, the expandable chamberincludes a port, from which a filler material can be introduced into orremoved from the expandable chamber. In certain embodiments, the port islocated on the chamber. According to one feature, the port includes anextension that extends away from the chamber, providing fluid access ata location other than where the expandable chamber is located. In anexample of such an embodiment, the extension end farthest from thechamber is positioned in an anatomical location of the patient whenimplanted in a patient, so that the end of the extension end, from whichthe filling material is injected or withdrawn, is easily accessibleusing no or minimally invasive procedures.

The expandable chamber can be sized and shaped so that it may be filledwith a variety of materials. Filler materials suitable to be used in thepresent invention are sterile, biocompatible and can be either inert ortherapeutically active. The filler materials can be selected fromvarious gas, liquid, gel, slurry, and/or phase-changing materials.

Another aspect of the invention provides a sling assembly with anexpandable chamber formed at least in part from permeable material. Partor all of the expandable chamber may be made from permeable material toallow certain components of the filler material to be released into thetissue environment surrounding the implanted sling. The chamber may befilled with a filler material including, for example, a therapeuticagent, which may be, for example, an analgesic or an anti-inflammatorydrug, a biological, a growth factor, a hormone, a genetic material, abiologically active agent that is beneficial to the patient, or anyother suitable agent. Components of the filler material may be releasedfrom the chamber through the permeable material.

In another aspect, the invention provides a method for adjusting supportfor a urethra including the step of adjusting the inflation of anexpandable chamber in a patient to provide a stable platform forsupporting the urethra. The expandable chamber may have any or all ofthe characteristics described above. The method may also include thestep of adjusting the degree to which the chamber is expanded from aport located at an easily accessible location spaced away from thelocation of the sling assembly.

The patient may be sitting or standing so that the torso is in aposition where most of the daily activities occur, in contrast to beingprostrate as is typically the case during the surgery for implanting asling assembly. Adjusting the sling tension while the patient's torso issubstantially upright allows determining the most suitable support ofthe urethra while the patient is engaged in everyday activities. Theminimally invasive nature of the method of the invention makes suchadjustment possible.

BRIEF DESCRIPTION OF THE DRAWINGS

The following figures depict certain illustrative embodiments of theinvention in which like reference numerals refer to like elements. Thesedepicted embodiments may not be drawn to scale and are to be understoodas illustrative of the invention and not as limiting in any way.

FIGS. 1A, 1B, and 1C depict a front perspective view of a sling assemblyhaving an expandable chamber in a contracted state (1A) and expandedstate (1B) and an expanded state of an alternative configuration (1C),respectively, according to illustrative embodiments of the invention.

FIG. 2 is a perspective cutaway view of an expandable chamber includesthrough channels having walls connecting the upper and lower sides ofthe chamber according to an illustrative embodiment of the invention.

FIG. 3 is a perspective cutaway view of an expandable chamber havingcord-like structures connecting internal surfaces of the upper and lowersides of the chamber according to an illustrative embodiment of theinvention.

FIG. 4 is a perspective cutaway view of an expandable chamber havingdividers connecting internal surfaces of the upper and lower sides ofthe chamber and forming sub-chambers that are in fluid communicationwith each other according to an illustrative embodiment of theinvention.

FIG. 5 is a perspective cutaway view of an expandable chamber withnon-contiguous dividers connecting inner surfaces of the upper and lowersides of the chamber and forming sub-chambers that are in fluidcommunication with each other according to an illustrative embodiment ofthe invention.

FIGS. 6A-6C depict various views of an expandable chamber havingaccordion-like sides connecting the upper and lower sides of the chamberaccording to an illustrative embodiment of the invention.

FIG. 7 is a front perspective view of a section of a sling assemblyincluding an expandable chamber according to an illustrative embodimentof the invention.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

As described above in summary, the invention in various embodiments isdirected to systems, methods, devices and assemblies relating to anexpandable chamber for supporting an anatomical site in a patient. FIGS.1A and 1B depict a front perspective view of a portion of a slingassembly 100 having an expandable chamber 104 according to anillustrative embodiment of the invention. More particularly, FIG. 1Ashows the expandable chamber 104 in a contracted state, while FIG. 1Bshows the expandable chamber 104 in an expanded state.

The illustrative sling assembly 100 includes a sling 102 and a sleeve124, which encloses, at least partially, the sling 102. The expandablechamber 104 includes a top side 114 and a bottom side 116. Theexpandable chamber 104 also includes axially extending front 110 andback 112 walls, along with two transversely extending side walls 106 and108. The walls 106, 108, 110, and 112 extend between the top 114 andbottom 116 sides to form the expandable chamber 104. Although the walls106, 108, 110 and 112 are depicted as being a single substantiallycontinuous and substantially square wall, this need not be the case. Forexample, one or more of the walls 106, 108, 110 and 112 may include acurved section, or may be formed as a continuous oval or circular wall.Additionally, they may be formed as individual structures bondedtogether in any suitable fashion. The expandable chamber 104 may alsoinclude more than four walls extending between the top 114 and bottom116 sides, for example, five, six, seven or eight walls. Additionally,the walls 106, 108, 110 and 112, in some embodiments, extend betweeninner surfaces of the top 114 and bottom 116 sides. In otherembodiments, one or more portions of the chamber 104 may be molded as aunitary structure.

According to the illustrative embodiment, the expandable chamber 104 isapproximately 1 cm wide and about 1 cm to about 6 cm long, with thethickness (height) dimension 122 of about 1 mm when in a non-expandedstate (FIG. 1A) and a thickness dimension 126 of up to about 10 mm (FIG.1B) when in an expanded state. In one preferred embodiment, the chamber104 has a thickness dimension 126 within the range of about 3 mm toabout 7 mm when in the expanded state. The expandable chamber 104 hassubstantially rectangular cross section taken both axially andtransversely. In another embodiment as depicted in FIG. 1C and describedbelow in the next paragraph, the expandable chamber 104 has a transversecross section may have a substantially planar or “U” shaped bottom edgeand a “U” shaped top edge with two side edges connecting the bottom edgeand the top edge. It should be noted that the above dimensions areparticularly well suited for supporting a urethra or bladder neck fortreating urinary incontinence, and that other suitable dimensions may beemployed depending on the anatomical site to be supported with the slingassembly 100.

According to one illustrative embodiment, the expandable chamber 104 isformed from any suitable biocompatible material and is constructed suchthat the chamber 104 expands substantially evenly and maintains the topside 114 substantially flat. One objective of maintaining the top side114 substantially flat is to discourage an anatomical site supported bythe chamber 104 from rolling or sliding off the top side 114. Accordingto a related embodiment, the top side 114 may be conceptually dividedinto three regions: two axially peripheral regions 132 and 134; and anaxially central region 130 located between the two axially peripheralregions 132 and 134. In one configuration, the central region 130includes the portion of the top side 114 that directly contacts theanatomical site to be supported. According to the illustrativeembodiment, the axially central region 130 is maintained at a height 140which is less than or equal to the height 136 of both axially peripheralregions 132 and 134 (FIG. 1C). When the axially central region 130 isdepressed in relation to the axial peripheral regions 132 and 134 of thetop 114, the top 114 forms a “U” shape of various depths of depression.According to embodiment, this height relationship is maintained when thechamber 104 is fully expanded. According to another embodiment, thisheight relationship is maintained during all states of chamber 104expansion. The above described height relationship ensures that anyanatomical site supported by the central region 130 will tend to slideor roll toward the center of the top side 114 rather than toward theperiphery, where it would be more likely to slide or roll off the topside 114. According to other illustrative configurations, the same or asimilar height relationship may exist laterally across the expandablechamber 104.

The expandable chamber 104 may be attached to the sling 102 by anysuitable mechanism including, but not limited to gluing, heat bonding,stitching, anchoring (see e.g. FIG. 7.) In the illustrative embodimentof FIGS. 1A and 1B, the expandable chamber 104 is glued to the bottomside 116 of expandable chamber 104. The sleeve 124, in the depictedembodiment, does not attach to the expandable chamber 104. Instead, thesleeve 124 has a gap along its top side, at least large enough toaccommodate the expandable chamber. The sleeve 124 may include a similargap along its bottom side, or alternatively, pass continuously under,but not bond to, the middle portion of the sling 102 and the bottom side116 of the expandable chamber 104.

As shown in FIGS. 1A and 1B, the illustrative expandable chamber 104includes a port 120 from which a filler material can be introduced intoor removed from the expandable chamber 104. The filling port 120 mayinclude an attached valve or a patch of self-sealing material. The valveis preferably a one-way valve to prevent undesired leakage of the fillermaterial. According to some illustrative embodiments, a suitable syringehaving a distal end sized and shaped to mate with and/or penetratethrough the port 120 may be employed to insert the filler material intoand/or remove the filler material from the expandable chamber 104.

The chamber 104, the port 120, and/or the suitable syringe arepreferably constructed of radio-opaque materials, or includeradio-opaque indicators, so that their location can be detected whilethe volume of the chamber 104 is adjusted by injecting or withdrawingthe filler material. According to another illustrative embodiment, theexpandable chamber 104 is constructed, at least in part, from aself-sealing material such as a silicone elastic. In this illustrativeembodiment, the filler material may be added or removed from the chamber104 via a syringe directly inserted into the chamber through theself-sealing material, without the need for a port, such as the port120.

According to a further illustrative embodiment, and as depicted in FIGS.1A and 1B, the expandable chamber 104 may include a port extension 128.When the sling assembly 100 is placed in a patient, it may be difficultto access the port 120 due to the location of the anatomical site beingsupported. The port extension 128 provides a fluid channel between theport 120 and an anatomical location remote from the anatomical sitebeing supported by the chamber 104. Preferably, the port extension 128leads to an anatomical location of the patient that is easily accessiblewith a minimally invasive or noninvasive procedure. In one example, theport extension 128 extends from the port 120 to a perineal area and maybe accessed percutaneously via a syringe needle. In another example, theport extension 128 extends from the port 120 to the surface of thepatient's body and can be accessed directly. The port extension 128 maybe formed with materials suitable for catheters.

Any one or more of a plurality of filler materials may be employed withthe expandable chamber 104 of the invention. Examples of suitable fillermaterials are preferably biocompatible, sterile, and can be either inertor therapeutically active. The filler materials can be selected, forexample, from gas, liquid, gel, slurry, or phase-changing materials. Anexample of a filler material that is a gas is sterilized air. Anotherexample of a filler material is sterilized saline. The filler materialmay also include materials that may solidify or liquefy depending onadded chemicals and/or temperature changes. These materials include, forexample, alginates, silicone fluid and gels, or Pluronic® F127.

In any of the foregoing illustrative examples or in any of theillustrative embodiments discussed below with regard to FIGS. 2-7, theexpandable chamber 104 may be formed at least in part from permeablematerial. The permeable material allows certain components of the fillermaterial to be released into the tissue environment surrounding theimplanted sling. The components of the filler material to be releasedmay include, for example, chemicals such as therapeutic agents, such asanalgesics, antibiotics, and anti-inflammatories, and/or biologicals,such as a growth factor, a hormone, a genetic material, and/or anybiological or chemical agent that is beneficial to the patient.According to another illustrative embodiment, the filler material thatis released from the chamber 104 may be biologically inert and simply bea by-product of reactions of the filler material, such as water releasedin solidification of alginate by the addition of calcium.

Any of the sling assemblies described herein may also be coated with atherapeutic agent, such as an analgesic, an anti-inflammatory, ananti-biotic, a growth factor, a hormone, a genetic material, or anybiologically active agent that is beneficial to the patient.

Additional illustrative embodiments of the invention will now bedescribed with reference to FIGS. 2 through 7. FIG. 2 depicts a cutawayview of an expandable chamber 202 in its expanded state. The chamber 202has through channels 216 connecting the external surfaces of the upperside 208 and the lower side 210. The through channels 216 may be round,square, rectangular, or any suitable shape, and they need not be of auniform shape or size, nor be evenly distributed throughout the chamber202. The chamber 202 also may have a port 204, with an optionalextension tube 206. The port 204 and extension tube 208 are of the typedescribed with respect to the port 120 and port extension of FIGS. 1Aand 1B. The upper side 208 and the lower side 210 are constructed ofmaterials that are flexible and may be expandable. According to theillustrative embodiment, the material forming walls 218 of the throughchannels 216 is resilient and flexible. Preferably, when the expandablechamber 202 is in a non-expanded state, such as shown in FIG. 1A, thewalls 218 of the through channels 216 contract and act to pull the upper208 and lower 210 sides together. As the chamber 202 expands, the walls218 of the through holes 218 stretch, but continue to exert a forcetending to pull the top 208 and bottom 210 walls together. Suchconstruction results in an even increase in thickness dimension (e.g.,122 and 126 of FIGS. 1A and 1B) of the chamber 202. As described abovewith respect to FIGS. 1A and 1B, such construction maintains the chamber202 in a condition that discourages an anatomical site, such as aurethra being supported by the chamber 202, from rolling or sliding offthe upper side 208. Another advantage of the illustrative embodiment ofFIG. 2 is that the through channels 216 allow tissues to grow into,around and through the chamber 202, thus tending to stabilize andintegrate the chamber 202 and any sling to which it is attached into thebody of the patient.

FIG. 3 shows a cutaway view of an expandable chamber 302 according toanother illustrative embodiment of the invention. The expandable chamber302 includes upper and lower sides 308 and 310, respectively, one ormore side walls 312, a port 304, and optionally, a port extension 306.

The expandable chamber 302 of FIG. 3 operates substantially like theabove described embodiments of FIGS. 1A, 1B and 2. However, instead ofthe through channels 216 of FIG. 2, the expandable chamber 302 employsone or more cord-like structures 316 for attaching inner surfaces of theupper 308 and lower 310 sides. The cord-like structures 316 operate in asimilar fashion to the through channels 216 to achieve a chamberconfiguration that discourages an anatomical site being supported fromrolling or sliding off the upper side 308. In some illustrativeembodiments, the cord-like structures 316 are all substantially the samelength to achieve a substantially flat upper side 308, excluding minorindentations 318 caused in the upper side 308 by cord connectionlocations. However, in other illustrative embodiments, the lengths ofthe cord-like structures 316 may vary to create, for example, a reducedthickness intermediate portion in the expandable chamber 302, such asthat discussed above with respect to the intermediate portion 130 ofFIG. 1. The cord-like structures 316 may be formed from the same orsimilar materials employed for the walls 218 of the through channels216, and with similar results.

FIG. 4 shows a cutaway view of another embodiment of an expandablechamber 402 in an expanded state. The expandable chamber 402 includesone or more internal dividers 416 that extend between inner surfaces ofits upper 408 and lower 410 sides, creating sub-chambers 420. Thesub-chambers 420 are not isolated from each other, but instead are influid communication through the openings 418 in the dividers 416. Theopenings 418 enable a filler material to disperse evenly between thesub-chambers 420 so that the expandable chamber 402 expands evenly. Thisfeature also causes the expandable chamber 402 to contract evenly inresponse to filler material being removed, for example, by way of theport 406 and, optionally, by way of the port extension tube 414. Theopenings 418 can be of any shape or size, as long as they allowsufficient fluid communication between the sub-chambers 420 for thefiller material to flow.

The internal dividers 416 operate in a similar fashion to the throughchannels 216 to achieve a chamber 408 configuration that discourages ananatomical site being supported from rolling or sliding off the upperside 408. In some illustrative embodiments, the dividers 416 are allsubstantially the same height to achieve a substantially flat upper side408, excluding minor indentations 422 caused in the upper side 408 bydivider connection locations. However, in other illustrativeembodiments, the heights of the dividers 416 may vary to create, forexample, a reduced thickness intermediate portion in the expandablechamber 402, such as that discussed above with respect to theintermediate portion 130 of FIG. 1.

FIG. 5 shows a cutaway view of an expandable chamber 502 according toanother illustrative embodiment of the invention. As shown in FIG. 5, ina similar fashion to the dividers 416 of FIG. 4, the dividers 516 extendbetween the upper side 508 and the lower side 510 of the expandablechamber 502. In place of the openings 418, the expandable chamber 502employs gaps 518 interrupting each of the dividers 516 so that they donot extend contiguously across the expandable chamber 502, but insteadare a series of short dividers with space in between each neighboringdivider. The gaps 518 provide a path through which filler material mayflow to provide substantially uniform expansion and contraction of theexpandable chamber 502. Alternatively, the chamber dividers may beformed from a material sufficiently permeable to enable the fillermaterial to flow between the sub-chambers. In such case the dividers mayextend contiguously across the expandable chamber. As in the case ofpreviously discussed embodiments, the expandable chamber 502 may includea port 506, which may be extended with a tube structure 508.

FIG. 6A shows a front perspective view of an expandable chamber 602having one or more accordion-like sides 612 according to anotherillustrative embodiment of the invention. FIG. 6B shows a magnifiedperspective view of a section 614 of the side 612 in a relativelycontracted state. FIG. 6B shows a magnified perspective view of the sidesection 614 in a relatively expanded state. As in the case of thepreviously discussed illustrative embodiments, the expandable chamber602 includes upper 608 and lower 610 sides, along with a side wall 612extending between the upper 608 and lower 610 sides. As also in the caseof the previously discussed embodiments, the side wall 612 may be formedas a plurality of discrete walls or as a continuous wall. Theillustrative expandable chamber 602 optionally includes a port 606 forinserting and removing filler material. The expandable chamber 602 alsooptionally includes a port extension 608, previously described. Asillustrated in FIGS. 6B and 6C, as filler material is added into thechamber 602, the accordion-like structure of the side wall 612 expandsfrom a height 614 to a height 615. In response to filler material beingremoved, the side wall contracts to a lower height. Any of the abovediscussed internal structures with respect the expandable chambers ofFIGS. 1-5, for example, for exerting a forced to pull the upper 608 andlower 610 sides together during filler removal, may be employed with theexpandable chamber 602 of FIGS. 6A-6C.

FIG. 7 depicts a section of a sling assembly 700 including an expandablechamber 702 according to another illustrative embodiment of theinvention. As in the case of the sling assembly 100 of FIG. 1, the slingassembly 700 includes a mesh sling 704 and a protective sleeve 706enclosing, at least partially, the sling 704. The protective sleeve 706includes an upper side 706 a and a lower side 706 b, between which thesling 704 is situated. The upper side 706 a of the sling 706 includes adiscontinuity located along its length. The sling assembly 700 includesa tab 706 enclosing a looped portion of the lower side 706 b of thesleeve 706. Cutting through the tab 706 and thus, the looped portion ofthe lower side 706 b, separates the sleeve 706 into two halves, whichmay be slide off the sling 704. According to one feature, the slingassembly 700 includes a valve 708 on one end of the expandable chamber702. The valve is so located that it will not come into contact with ananatomical location that the sling assembly supports when placed in apatient. As shown, the expandable chamber 702 may have an elongatedconfiguration and include axially distributed sub-chambers 702 a-702 i,which may be in fluid communication for even expansion and contraction.Alternatively, the sub-chambers 702 a-702 i, along with any of the abovediscussed sub-chambers, may be expanded and contracted individually tocreate a desired chamber shape.

According to other illustrative embodiments, the invention is directedto a method for adjusting support to an anatomical location, the methodincluding the step of adjusting the degree of expansion of an expandablechamber in a patient such that a tissue contacting upper surface of theexpandable chamber is maintained in a position that discourages theanatomical site from rolling or sliding off of the upper surface.According to a further illustrative embodiment, the method includesadding and/or removing filler material to control a height/thickness ofthe expandable chamber. According to one illustrative embodiment, themethod includes maintaining the upper surface in a substantially flatconfiguration. According to another illustrative embodiment, the methodincludes maintaining the upper surface in a substantially levelconfiguration relative to the anatomical site. According to a furtherillustrative embodiment, the method includes maintaining a portion of aperiphery of the expandable chamber at a greater height/thickness thanan intermediate portion of the expandable chamber. According to anotheralternative embodiment, the method includes maintaining a substantiallyuniform height/thickness across the entire expandable chamber, exceptfor example, for indentations in the upper and/or lower surfaces of theexpandable chamber caused by internal interconnections between upper andlower sides of the expandable chamber.

According to another feature of the invention, the height of theexpandable chamber may be adjusted while the patient is sitting and/orstanding so that the torso is in a position in which most dailyactivities occur. Adjusting the sling tension while the patient's torsois substantially upright allows determining the most suitable support ofthe anatomical site (e.g., a patient's urethra) while the patient isengaged in everyday activities. The minimally invasive nature of themethod of the invention makes such adjustment possible.

The invention described herein may be employed with various slings,sling assemblies, and delivery devices, sling assembly-to-deliverydevice association mechanisms, and implantation approaches. Withoutlimitation, examples of the foregoing are disclosed in U.S. Pat. No.6,042,534, entitled “Stabilization sling for use in minimally invasivepelvic surgery,” U.S. Pat. No. 6,755,781, entitled “Medical slings,”U.S. Pat. No. 6,666,817, entitled “Expandable surgical implants andmethods of using them,” U.S. Pat. No. 6,042,592, entitled “Thin softtissue surgical support mesh,” U.S. Pat. No. 6,375,662, entitled “Thinsoft tissue surgical support mesh,” U.S. Pat. No. 6,669,706, entitled“Thin soft tissue surgical support mesh,” U.S. Pat. No. 6,752,814,entitled “Devices for minimally invasive pelvic surgery,” U.S. patentapplication Ser. No. 10/774,826, entitled “Devices for minimallyinvasive pelvic surgery,” U.S. patent application Ser. No. 10/774,842,entitled “Devices for minimally invasive pelvic surgery,” U.S. patentapplication Ser. No. 10/939,191, entitled “Devices for minimallyinvasive pelvic surgery,” U.S. patent application Ser. No. 10/460,112,entitled “Medical slings,” U.S. patent application Ser. No. 10/092,872,entitled “Medical slings,” U.S. patent application Ser. No. 10/093,371,entitled “System for implanting an implant and method thereof,” U.S.patent application Ser. No. 10/093,398, entitled “System for implantingan implant and method thereof,” U.S. patent application Ser. No.10/093,424, entitled “System for implanting an implant and methodthereof,” U.S. patent application Ser. No. 10/093,450, entitled “Systemfor implanting an implant and method thereof,” U.S. patent applicationSer. No. 10/093,498, entitled “System for implanting an implant andmethod thereof,” U.S. patent application Ser. No. 10/094,352, entitled“System for implanting an implant and method thereof,” U.S. patentapplication Ser. No. 10/631,364, entitled “Bioabsorbable casing forsurgical sling assembly,” U.S. patent application Ser. No. 10/641,192,entitled “Medical slings,” U.S. patent application Ser. No. 10/641,376,entitled “Spacer for sling delivery system,” U.S. patent applicationSer. No. 10/641,487, entitled “Systems, methods and devices relating todelivery of medical implants,” U.S. patent application Ser. No.10/642,395, entitled “Systems, methods and devices relating to deliveryof medical implants,” U.S. patent application Ser. No. 10/642,397,entitled “Systems, methods and devices relating to delivery of medicalimplants,” U.S. patent application Ser. No. 10/832,653, entitled“Systems and methods for sling delivery and placement,” U.S. patentapplication Ser. No. 10/918,123, entitled “Surgical slings,” and U.S.patent application Ser. No. 10/973,010, entitled “Systems and methodsfor sling delivery and placement,” the entire contents of all of whichare incorporated herein by reference.

1. A sling assembly comprising: a sling having first and second ends andan expandable chamber located intermediate to the first and second ends,the expandable chamber including upper and lower sides, and wheninflated, the upper side being substantially flat.
 2. The sling assemblyof claim 1, wherein the upper and lower sides are attached at one ormore locations internal to the expandable chamber.
 3. The sling assemblyof claim 2, wherein the one or more locations include at least onethrough passage between an outer portion of the upper side and an outerportion of the lower side, the through passage including a wallattaching the upper and lower sides.
 4. The sling assembly of claim 2,wherein the one or more locations include at least one divider extendingbetween the upper and lower sides for dividing the expandable chamberinto a plurality of sub-chambers in fluid communication with each other5. The sling assembly of claim 2, wherein the one or more locationsincludes at least one cord-like structure for attaching the upper andlower sides.
 6. The sling assembly of claim 2, wherein the one or morelocations include one or more side walls extending between the upper andlower sides and located along a periphery of the expandable chamber. 7.The sling assembly of claim 2, wherein the upper side of the expandablechamber is substantially rigid.
 8. The sling assembly of claim 2,wherein the upper side of the expandable chamber is pre-shaped to fitthe contour of the urethra.
 9. The sling assembly of claim 1, whereinthe expandable chamber includes a height adjustable side wall, attachedat one edge to the upper side and at another edge to the lower side, andhaving an accordion-like structure.
 10. The sling assembly of claim 9,wherein the height adjustable wall extends along a width of theexpandable chamber.
 11. The sling assembly of claim 9, wherein theheight adjustable wall extends along a length of the expandable chamber.12. The sling assembly of claim 1, wherein the expandable chamber isformed at least in part from a self-sealing material.
 13. The slingassembly of claim 1 comprising a port for at least one of inserting andremoving a filler material into or from, respectively, the expandablechamber.
 14. The sling assembly of claim 13, wherein the port includesan extension tube for extending from the expandable chamber to alocation remote from the expandable chamber for providing fluid accessto the expandable at a location other than where the expandable chamberis located.
 15. The sling assembly of claim 1, wherein the expandablechamber is sized and shaped for expansion by inserting at least one of agas, liquid, gel, solid particles, particulate slurry, or aphase-changing material.
 16. The sling assembly of claim 1, wherein theexpandable chamber is sized and shaped for expansion with saline. 17.The sling assembly of claim 1, wherein the expandable chamber is sizedand shaped for expansion with air.
 18. The sling assembly of claim 1,wherein the expandable chamber is formed at least in part from apermeable material.
 19. The sling assembly of claim 18, wherein theexpandable chamber is sized and shaped for expansion with a therapeuticagent.
 20. The sling assembly of claim 19, wherein the therapeutic agentincludes at least one of a chemical, a biological, a growth factor, agenetic material, and a hormone.
 21. The sling assembly of claim 1,wherein the sling is coated with a therapeutic agent.
 22. A method ofsupporting an anatomical site in a patient comprising the steps of:adjusting a thickness of an expandable chamber while maintaining anupper side configured to discourage the anatomical site from travelingoff of the upper side.
 23. The method of claim 22 including maintainingthe upper side in a substantially flat configuration to discourage theanatomical site from traveling off the upper side.
 24. The method ofclaim 22 including maintaining a substantially consistent change inthickness throughout the expandable chamber during the adjusting. 25.The method of claim 22 including maintaining a peripheral portion of theexpandable chamber at a greater thickness than an intermediate portionof the expandable chamber during the adjusting.
 26. The method of claim22 including providing a filler material to the expandable chamber froma location remote to the expandable chamber to perform the adjusting.